today president obama warned assad and his forces that the world is watching. the president said they will be held accountable if they use chemical weapons or let them fall into the hands of terrorists. but in secret testimony this week, congressional committees were told some of these deadly weapons are, in effect, locked and loaded. and that the regime plans to use them. israeli intelligence agrees, i'm told, and believe the trigger could well be if aleppo, syria's largest city, falls to the rebels. if that were to happen, the president and netanyahu have military plans in place to stop the weapons from getting into the hands of terrorists. and of course, brian, the other big concern for the u.s. and israel is iran. just today iran's supreme leader threatened to level israeli cities if israel sights the nuclear program. lots to worry about. >> andrea mitchell, part of our team covering the middle east this week. andrea, thanks. >>> the national weather service has told the folks along the red river in fargo, north dakota, to prepare for perhaps one of the top